Coupling unit



April 9, 1957 c. J. DoYLE 2,788,234

couPLING UNIT Filed May 19. 1952 im@ .Cedric J. Da@ B r A Home y* COUPLING UNIT Cedric J. Doyle, Grand Rapids, Mich.

Application May 19, 1952, Serial No. 288,663

1 Claim. (Cl. 287-403) The present invention relates to equipment for driving holes through sections of earth. A typical illustration of the possibility of use of this operation is in situations along a paved roadway in which a watermain is disposed on one side of the road. In order to provide a connection to this watermain for a house on the opposite side of the road, the conduit must be run under the paved portion of the highway and sidewalk. To dig a passage underneath the roadway or to rip up the road would be a very expensive operation. It has been found that such excavations are unnecessary, due to the possibility of actually driving a hole underneath the concrete through which a suitable conduit may be threaded. The proce dure for performing this operation involves rst the digging of a pit adjacent the road and of suicient depth for a man to stand and operate a conventional air hammer at approximately waist height. A length of tube provided with a point is then directed into the side of the pit along the line that it is desired the conduit shall follow underneath the roadway. The application of the air hammer to the back of this pointed pipe gradually forces it into the earth up to the end. A second length of pipe is then secured to the one that has been previously driven, and the air hammer again applied to the free end. Repetition of this process gradually establishes a long columnar member functioning as a gigantic needle, the point of which is gradually forced through the earth under the road to where it emerges in a pit on the opposite side. The usual practice is for a water conduit to either then be shoved back through the hole as the boring column is withdrawn with block and tackle, or the conduit may actually be attached to the exposed end of the column so that it is forceably dragged back through to the opposite side.

The problem in the execution of this operation has been the assembly and disassembly of the various segments of the boring column. Conventional practice provides for a series of short lengths of pipe to be welded together and cut apart with a torch as the occasion arises. The completion of such welds is not only a time-consuming operation, but the inevitable projection of the welds beyond the cylindrical surface of the pipe presents roughened areas making more diicult the driving of the member through the earth. It is also obvious that the re-use of the pipe segments is interfered with, due to accumulative elfect of the large number of welds and cut areas tending to distort the axis of the pipe from that of a true cylinder. Any substantial distortion of this nature will make it extremely diicult to direct the assembled column along a proper path.

The present invention provides a driving coupling for the segments constituting the boring column, the important characteristics of this coupling being ease of assembly and disassembly while maintaining the proper characteristics necessary for the driving operation. The detachability of the elements of the coupling make possible the continued re-use of the pipe segments and eliminate the time-consuming series of welding operations.

" nited States Patent O r"ice A2,788,234 Patented Apr. 9, 1957 The features of the present invention will be discussed in detail through .an analysis of the particular embodiments illustrated in the accompanying drawings. In these drawings,

Figure 1 presents a diagram showing the manner of driving a hole underneath a roadway.

Figure 2 presents an axial section through a pipe coupling embodying the present invention.

Figure 3 presents a section on the plane 3-3 of Figure 2.

Figure 4 presents a section on the plane 4--4 of Figure 2.

Figure 5 presents an elevation of one member of the coupling unit.

Figure 6 shows an exploded view of a segment of the driving column showing its relationship to the other `components of the column, including the cross bolt used to lock the coupling components together.

Figure 7 illustrates a driving tting which is secured to the column at the exposed end for transmitting the forces from the air hammer to the column.

Referring to Figure 1, a section is shown through the area surrounding and underneath a paved roadway 10. Sidewalk-s are shown at 11 and 12, and a section of earth is generally indicated a-t 13 underneath the roadway and sidewalks through which it is desired that a hole be driven in order to communicate between the left side of the road and the watermain shown exposed at 14. As a preliminary to the driving operation, suitable pits rare dug as indicated at 15 and 16, the pit 16 being of suflicient depth for a man indicated at 17 to operate the air hammer i8 in a generally horizontal position. A driving column i9 (composed of the segments to be discussed hereinafter) is progressively assembled during the driving operation, and is forced through the section of earth 13 to the pin i5 where it emerges. Suitable connections can be made with another conduit to the watermain 14, and the free end of that conduit can then be drawn back through the hole established by the column 19 to where it can be connected in the pit 16 to whatever building is involved.

Referring to Figure 2, two of the segments making up the column 19 are indicated at 20 and 21.. These two segments `are joined together by the coupling unit composed of the members 22 and 23, held in assembled position by the cross bolt 24. These coupling members are in similar form, and include a base portion generally indicated at 25 and 26, and a hook portion identified at 27 and 28. The base portions 25 and 26 are preferably secured to the segments 20 :and 21 (preferably sections of steel pipe) by plug welding as indicated at 29, 30, 31, and 32. A plug weld is merely a weld which is performed through an aperture in an outer member (such as the wall of the pipe of the segments 20 and 21) so that the weld is in intimate contact with an inner member and thereby secures the two members together.

Referring 4to Figure 6, the hook portions 27 and 28 are provided with end surfaces 33 :and 34 disposed to contact the opposite surfaces 35 and 36 on the base portions 25 and 26. The surfaces 33 and 34, together with the surfaces 35 and 36, are so disposed relative to the axis of the coupling that the clamping action established by the cross bolt 24 positioned in the bores 37a` and 37b either creates a tendency for the components to separate slightly in an axial direction, or produces movement completely in a radial direction. In contrast to this movement, the hook portions 27 and 28 are also provided with locking surfaces 38 and 39. The important relationship existing between the surfaces 38 and 39, the surfaces 33 and 34, and the surfaces 35 and 36, is that a jamming action takes place as the cross bolt 37 is tightened. This jamming :action establishes solid engagement between at least one set of surfaces 34-35 or 33-36 along with the surfaces 38 and 39., Driving, action therefore takes place at the engagement of the broad end surfaces of the hook portions 27 and 28 (preferably both of them), and tension is transmitted permitting withdrawal of the driving column through the engagement of the lockingl sur- :faces 33 and 39, all Without stressing the crossv bolt 24 directly in shear. In Figure 6, the right-hand portion of the View indicates the coupling mem-ber in'4 the assembled and tightened position. It is preferahlethat the tolerances of manufacture be: such 4that driving action lactually produce forces which are, transmitted at the points indicated by the arrows 40 and 41, so thatl a substantially balanced force about the axis of the column is established.

Referring tof Figure. 7,.v a. special form of end-fitting is used which is adapted to transfer the forces from the air hammer Vin to the column I9. A base portion 4Z, is provided with a hook portion 43 formed in similar fashion the hook portions. previously discussed, so that the unit indicated inv Figure 7 can be attached in the fashion indiA cated in Figure 6. The Figure 7 fitting,` however,A is kept at the exposed driving end of the column so that the recess 44A is positioned to receive the projecting driving tool of the hammer 1S.. As the column is driven into the earth up to the tting shown in Figure 7, that fitting is removed and another section, of column secured in position. The Iitting of Figure 7 is then secured at the free end of the new section, and the driving process is repeated.

illustrative purposes only and are not to be considered as,a 1irnitation,l1pon the scope of the appended claim, In the claim, -it is my intention to claim the entire invention disclosed herein, except as I 1am limited by the prior art.

l claim:

A coupling unit for connecting segments of a hole-driving column, comprising: rst and second coupling members, each having a 'oase portion, a hook portion, said hook portion having on its end a surface abutting a surface on the base portion of the other of said coupling members, said hook portion :also having an intermediate surface facing substantially oppositely to said end surface and in a plane inclined to the plane ofV said end surface, and engaging a similar surface on the other of said coupling members; and' clamping means including a cross boit urging said coupling members into Wedging engagei'nent between said respective intermediate, base portion, and end surfaces, said coupling members engaging each other only on said; intermediate, base portion, and end surfaces.

References Cited in the. file of this` patent UNITED STATES PATENTS 910,510 Davis Jan. 26, 1909 1,019,110 'Woods Mar. 5, 1912 1,514,652 Burmaster Nov. 11, 1924 1,853,578 Ross Apr. 12, 1932 2,680,034 Robbins June 1, 1954 FOREIGN PATENTS 264,258, Germany of 1913 784,145 France of 1935 

